rbd: add functions for initializing global variables

When the rbd-driver starts, it initializes some global (yuck!) variables
in the rbd package. Because the rbd-driver is moved out into its own
package, these variables can not easily be set anymore.

Introcude SetGlobalInt(), SetGlobalBool() and InitJournals() so that the
rbd-driver can configure the rbd package.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/rbd/globals.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2021 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rbd
+
+import (
+	"fmt"
+
+	"github.com/ceph/ceph-csi/internal/journal"
+)
+
+const (
+	// volIDVersion is the version number of volume ID encoding scheme.
+	volIDVersion uint16 = 1
+)
+
+var (
+	// CSIInstanceID is the instance ID that is unique to an instance of CSI, used when sharing
+	// ceph clusters across CSI instances, to differentiate omap names per CSI instance.
+	CSIInstanceID = "default"
+
+	// volJournal and snapJournal are used to maintain RADOS based journals for CO generated
+	// VolumeName to backing RBD images.
+	volJournal  *journal.Config
+	snapJournal *journal.Config
+	// rbdHardMaxCloneDepth is the hard limit for maximum number of nested volume clones that are taken before flatten
+	// occurs.
+	rbdHardMaxCloneDepth uint
+
+	// rbdSoftMaxCloneDepth is the soft limit for maximum number of nested volume clones that are taken before flatten
+	// occurs.
+	rbdSoftMaxCloneDepth              uint
+	maxSnapshotsOnImage               uint
+	minSnapshotsOnImageToStartFlatten uint
+	skipForceFlatten                  bool
+
+	// krbd features supported by the loaded driver.
+	krbdFeatures uint
+)
+
+// SetGlobalInt provides a way for the rbd-driver to configure global variables
+// in the rbd package.
+//
+// TODO: these global variables should be set in the ControllerService and
+// NodeService where appropriate. Using global variables limits the ability to
+// configure these options based on the Ceph cluster or StorageClass.
+func SetGlobalInt(name string, value uint) {
+	switch name {
+	case "rbdHardMaxCloneDepth":
+		rbdHardMaxCloneDepth = value
+	case "rbdSoftMaxCloneDepth":
+		rbdSoftMaxCloneDepth = value
+	case "maxSnapshotsOnImage":
+		maxSnapshotsOnImage = value
+	case "minSnapshotsOnImageToStartFlatten":
+		minSnapshotsOnImageToStartFlatten = value
+	case "krbdFeatures":
+		krbdFeatures = value
+	default:
+		panic(fmt.Sprintf("BUG: can not set unknown variable %q", name))
+	}
+}
+
+// SetGlobalBool provides a way for the rbd-driver to configure global
+// variables in the rbd package.
+//
+// TODO: these global variables should be set in the ControllerService and
+// NodeService where appropriate. Using global variables limits the ability to
+// configure these options based on the Ceph cluster or StorageClass.
+func SetGlobalBool(name string, value bool) {
+	switch name {
+	case "skipForceFlatten":
+		skipForceFlatten = value
+	default:
+		panic(fmt.Sprintf("BUG: can not set unknown variable %q", name))
+	}
+}
+
+// InitJournals initializes the global journals that are used by the rbd
+// package. This is called from the rbd-driver on startup.
+//
+// TODO: these global journals should be set in the ControllerService and
+// NodeService where appropriate. Using global journals limits the ability to
+// configure these options based on the Ceph cluster or StorageClass.
+func InitJournals(instance string) {
+	// Use passed in instance ID, if provided for omap suffix naming
+	if instance != "" {
+		CSIInstanceID = instance
+	}
+
+	volJournal = journal.NewCSIVolumeJournal(CSIInstanceID)
+	snapJournal = journal.NewCSISnapshotJournal(CSIInstanceID)
+}

internal/rbd/rbd_util.go

@@ -200,8 +200,7 @@ type migrationVolID struct {
 	clusterID string
 }
 
-var (
-	supportedFeatures = map[string]imageFeature{
+var supportedFeatures = map[string]imageFeature{
 	librbd.FeatureNameLayering: {
 		needRbdNbd: false,
 	},
@@ -220,14 +219,11 @@ var (
 		needRbdNbd: true,
 		dependsOn:  []string{librbd.FeatureNameExclusiveLock},
 	},
-	}
+}
 
-	krbdFeatures uint64 // krbd features supported by the loaded driver.
-)
-
-// getKrbdSupportedFeatures load the module if needed and return supported
+// GetKrbdSupportedFeatures load the module if needed and return supported
 // features attribute as a string.
-func getKrbdSupportedFeatures() (string, error) {
+func GetKrbdSupportedFeatures() (string, error) {
 	// check if the module is loaded or compiled in
 	_, err := os.Stat(krbdSupportedFeaturesFile)
 	if err != nil {